Carl Brown 3 Pros:- 3 vanes at once- adjustable vane placer with point markers- balanceCons:- no point marker on the (base) adjuster for arrow thickness making it very fiddly and not easy to get accurate.- the plastic arms are not stiff enough at the base joint. This means that you cannot put all 3 arms up at once as the 3rd arm will twist. You can put two up at once and then carefully the third arm to ensure that all 3 vanes are equidistant.Other points:- what is not shown in the picture is a small elastic band to ensure the arms are kept up right if the vane base is a bit thick otherwise only the lower part will have pressure on the arrow.I was considering returning for a (cheaper) single flight machine, however, I have not seen the actual product (which might be fiddlier) so chose to keep purely because of the convenience of 3 vanes at once.